The topic of the thesis "The role of social networks in the development of social competencies of adolescents" aims to explore the relationship between social networks and social competencies of adolescents. Since the popularity of social networks is changing rapidly, the social networks TikTok and Instagram, which are currently receiving a lot of attention from adolescents and young adults, were chosen for the study. The theoretical part of the paper focuses on explaining the concepts of TikTok and Instagram social networks and their characteristics. The concept of social competencies, the nature of social competencies in the age of adolescence, and the educational context of social competencies are also explained in further research. The empirical part of the paper examines the relationship between TikTok and Instagram social networks and adolescents' social competencies, which also reflects the aim of this research. Considering the importance of social competencies in the educational process and their development, the positive or negative relationship between the social networks TikTok and Instagram and the level of social competencies development of adolescents is investigated. The analysis of data collected through questionnaires revealed a positive correlation between the use of the social network TikTok and adolescents' social competencies, while the use of the social network Instagram showed no correlation with adolescents' social competencies. In the further chapters of this thesis, the results of the research will be presented in more detail, the limitations of the research will be pointed out, and final considerations and foundations for further research on the mentioned or related topics in the context of pedagogy will be given.